Animated GIF not fading in

Question

I created an image that's kind of in three parts. The left piece, a plus sign, the right piece. The idea was that I'd create an animated GIF and start with the left piece, then fade in the plus sign, then fade in the right piece.

So I create an image with the background for the whole picture and the left piece in a layer. Then I generated 4 layers for the plus sign at opacities of 25%, 50%, 75%, 100%. When I turn the visibility off on these layers and turn it on in order it fades in nicely. (I intend to do this with the right piece too.)

So I then run Filters->Animation->Playback and the plus sign drops in immediately and waits for the length of time of all four layers and then the right piece drops in. So there's no fade.

Am I missing a piece.

I did the same thing yesterday and you can see the result at http://www.pizzainthecloud.com, but I'm using a different route this time and I don't understand why this isn't working.

Answer 1

There is no support for partial opacity in the GIF format, so your "Combine" layers have a full opacity. You can do what you want by generating full frames (background, in which you add a + with partial opacity) and putting the resulting frames in "replace" mode (which is possibly what you did already).